Improvement in dams



UNITED STATES PATENT OFFICE.

IMPROVEMENT IN DAMS.

Speclication forming part of LcttcrsfPatcnt No; 36,34%, dated September 2, 1862.

To all wwm t may concern:

Beit known that I, JOHN DU Bois, of Willianisport, in the county of Lycoming and State i of Pennsylvania, have invented a new and usefulv Improvement in Self-Regulating Chutes for `Passing Logs, Rafts, Boats, &c., Through Dams, and I do hereby declare that the' following is a. full and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference 'markedthereon, likev lettersin the several figures indicating the same or analogous parts, and in which drawings-l 4Figure lis a perspective view of my improved k chutegLFig. 2, a side' View ofv Fig.v l in the line .fr ar,- FigL, a section in the line 1/ y, Fig. 2; and Fig. 4, a view showing the 'jointing of the apron to the forward end of the chute. I l

The nature of my invention consists infso constructing a chute for passing boats, logs,

. rafts, and the like through a dam7 ythat the available working depth of water lWithin the chute shall remainthe same; notwithstanding the depth of the water above the dam may vary and draw down during the act of so passing boats, logs, and rafts. f To this end lsecure permanently in the dam A a main flume hav`v ing sides b b (one of them not shown in the drawings) and ilooring c, the Alower end of the flume'being left at all times open, and the upper end having a head-gate, D,with asmall dood-gategh'applied thereto, as shown in Fig, 1. To the main flume a side flume, E, isvapplied, as shown, the latter being framed77 .into the former so as to hold both permanently together, thc-width of the side flume being, say, onclhalf of the main fiume, but of the same height, and both having their bottoms on the saine horizontal plane. From'theflumecircular openings g', cut through the sides b b of the main fiume, as indicated in Fig. 2..l

Within the mainiilume, as represented, I apply an apron of peculiar constructiomits forward portion, H, being attached to its rear portion, H', by hinges i, and in such manner as to allow therise and fall ofthe apron, the rear end ofthe portion H of the apron being securely attached to the hinge F', as indicated in Figs. 1 and 4.v To the under side of theA part H of the apron,as shownin Figs. 1 and 3,a

cleat, l, is secured, having bearings l to engage with and slide in horizontal slotsor ways m, cut in the sides b'b of the main ume. It will'thus be seen that the apron H H mits rise and fall will articulate upon the hinge F', and that the length ot'- the ways in will govern the height at which theapex n of the apron can rise within the main ilume. In other words, the waysm arecf such length as to allow the apron to be drawn down flat upon the floor of the main Hume, or have its apex nthrown up to its greatest desirable hei htas indicated e apron has fallen flatly, ornearly so', upon the bottom c of the main floor. Such being the condition of the chute, the operator will rst;

proceed to .elevate the gate d', which act will permit the water from the side flume, E, to enter the main flume beneath the apron through the opening di, thus raising the apron from its flat position upon the floor c into the position, say, as shown in red line in Fig. 1. From such position it is evident that the apron may still be further elevated until it has attained itsv maximum height Within the main flume. But

vthe desired elevation of the apron, between its extremes of elevation fand depression, will depend valtogether upon the depth of water required above its apex n for the passage of the raft without striking or touching the apron at such point. supposing such depth to be one foot, the operator will'allow the water to iiow into the main flume from the side flume, E, and

'beneath the apron, until the point n of thev -raft by any proper means.

' enabled to pass logs,

apron is elevated to a' point one foot below the over the apex of the apron, after which the flood-gate D may 'be entirely removed, orelevatedont of the Vway Under such condition of the chute it is evident'that so long as the head of water in the pond above the dam remains the same, the depth .of water will be one foot above thehighest point of the apron; and, further, that as the water A draws down,the pressure above and beneath theapron will be such` as to permit it to-fall inexact ratio with the fall of the meantime always maintaining the specified depth of water abo've the point n of the apron.v

Of course afterthe apron has fallen down to its extreme limit a continued decrease of head of water in the pond would in like manner decrease the depth of water above the apron.

I wouldhere state that after` the apron is once made to assume the position shown in Fig. 1, the nood-gate D may be dispensed with, in which ease the part H of the apron will Aof itself act as aimain gate to the main flume.

Dy constructing a chute as described, I vam I lumber, rafts, boats, or otheriloating material from a point ahovethe `dam to a `point below itwithout,subjecting` them to a perpendicular fall of water between thetwo points during their passage, at the same. time maintaining a' given depth of water abovcthe apron, while the pond above the dam is beine drawn down.

ofthe passage of the head of water A', but

at the opposite 'extremity of the'apron,

'ln the eourseof the operation of the chute, if there should be any hesi taney of the apron to become depressed as the head of water draws down above the dam, the depression of the apron may be accelerated, either by slightly depressing the `rate d the gate d. i Havingthns described my invention, what Iclaim as new, land desire ters Patent of the Unitedl States.l is- 1'. In a dam-chute whehis operated by hydrostatic pressure beneath an apron, adivided apron `having its lparts hinged at the point of junction, substantially as and for the purpose described.

2. In a dam-chute having a divided apron, aixedarticulating, joint at Vone extremity of the apron, in combination with a sliding joint for the purpose set forth.

8. Adam-chute tions II Il', hinged 'together at their junction,

as at fi, the lower seetionpH, articulating upon v a fixed hinge, and the upper end of the scction II `traveling in a horizontal slot at the bottom of thelume, the whole being operated substantially in the,` manner and for the purpos described.

Witness myhand and 4seal inthe matter oi my application for apatent vfor an improved ehnteiorpassinglogs, rafts, boats,&c., through dams, this 29th day of July, A. D. 1R62. JOHN DU B()IS. [L s1] Witnesses:

GUsTAvUs DIETE'RICH, EDWIN S. JACOB.

or by slightly opening f to secure by Let-I having an apron made in sec, 

